BOSTON – When it comes to avoiding strokes, consumers should choose chicken over beef, according to a recent Harvard study published in the journal Stroke. “The main message from this paper is that the type of protein or the protein package is really important for the risk of stroke,” Frank Hu at the Harvard School of Public Health said of the study, according a Reuters article. “We have to consider protein in the context of the foods,” Hu said.

Hu and a team of researchers collected data for more than 20 years from two health surveys that tracked nearly 130,000 men and women from roughly middle age to their senior and elderly years. Nearly 1,400 men and more than 2,600 women had a stroke.

In order to see what influence different types of protein had on the risk of stroke, the researchers divided up the people in the study based on how much red meat, poultry, fish, dairy and other sources of protein they typically ate each day.

A serving of red meat was considered to be 113 to 170 g (4 to 6 oz) of beef, or a hamburger patty. A serving of poultry was considered to be 113 g.

There was a 28 percent increase in the risk of stroke among the men who ate more than two servings of red meat each day, compared to men who on average had a third of a serving of red meat each day. Among the women surveyed, there was a 19 percent higher risk of stroke for those who ate nearly two servings of red meat a day compared to those who ate less than half a serving each day.

Swapping out red meat for different types of proteins lowered stroke risk. Exchanging one serving of poultry lowered stroke risk by 27 percent, a serving of nuts or fish was linked to a 17 percent drop, and a serving of dairy dropped the risk by 10 to 11 percent.

According to Adam Bernstein, lead author of the study, there was no proof that beef is to blame for the increased number of strokes, however, he said fat and iron in red meat could be a factor. An earlier study led by Susanna Larsson at the Karolinska Institute in Stockholm, Sweden, also found that eating red meat had a link to the risk of stroke.

One surprise was that fish seemed to offer no protection against stroke, although Bernstein said it was possible that the benefits of fish depend on how it's served.